(-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK
We previously showed that the mitogen-activated protein (MAP) kinase superfamily, p44/p42 MAP kinase, p38 MAP kinase, and stress-activated protein kinase (SAPK)/c-Jun N-terminal (JNK), positively plays a part in the platelet-derived growth factor-BB- (PDGF-BB-) stimulated synthesis of interleukin-6...
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2008-01-01
|
| Series: | Mediators of Inflammation |
| Online Access: | http://dx.doi.org/10.1155/2008/291808 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832562984117862400 |
|---|---|
| author | Shinji Takai Rie Matsushima-Nishiwaki Seiji Adachi Hideo Natsume Chiho Minamitani Jun Mizutani Takanobu Otsuka Haruhiko Tokuda Osamu Kozawa |
| author_facet | Shinji Takai Rie Matsushima-Nishiwaki Seiji Adachi Hideo Natsume Chiho Minamitani Jun Mizutani Takanobu Otsuka Haruhiko Tokuda Osamu Kozawa |
| author_sort | Shinji Takai |
| collection | DOAJ |
| description | We previously showed that the mitogen-activated protein (MAP) kinase superfamily, p44/p42 MAP kinase, p38 MAP kinase, and stress-activated protein kinase (SAPK)/c-Jun N-terminal (JNK), positively plays a part in the platelet-derived growth factor-BB- (PDGF-BB-) stimulated synthesis of interleukin-6 (IL-6), a potent bone resorptive agent, in osteoblast-like MC3T3-E1 cells while Akt and p70 S6 kinase negatively regulates the synthesis. In the present study, we investigated whether (-)-epigallocatechin gallate (EGCG), one of the major green tea flavonoids, affects the synthesis of IL-6 in these cells and the mechanism. EGCG significantly reduced the IL-6 synthesis and IL-6 mRNA expression stimulated by PDGF-BB, EGCG reduced the PDGF-BB-stimulated IL-6 synthesis also in primary-cultured osteoblasts. EGCG had no effect on the levels of osteocalcin and osteoprotegerin in MC3T3-E1 cells. The PDGF-BB-induced autophosphorylation of PDGF receptor β was not suppressed by EGCG. The PDGF-BB-induced phosphorylation of p44/p42 MAP kinase and p38 MAP kinase was not affected by EGCG. On the other hand, EGCG markedly suppressed the PDGF-BB-induced phosphorylation of SAPK/JNK. Finally, the PDGF-BB-induced phosphorylation of Akt and p70 S6 kinase was not affected by EGCG. These results strongly suggest that EGCG inhibits the PDGF-BB-stimulated synthesis of IL-6 via suppression of SAPK/JNK pathway in osteoblasts. |
| format | Article |
| id | doaj-art-e6ae2c1af7334cacb6e0541db863dab7 |
| institution | Kabale University |
| issn | 0962-9351 1466-1861 |
| language | English |
| publishDate | 2008-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Mediators of Inflammation |
| spelling | doaj-art-e6ae2c1af7334cacb6e0541db863dab72025-02-03T01:21:21ZengWileyMediators of Inflammation0962-93511466-18612008-01-01200810.1155/2008/291808291808(-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNKShinji Takai0Rie Matsushima-Nishiwaki1Seiji Adachi2Hideo Natsume3Chiho Minamitani4Jun Mizutani5Takanobu Otsuka6Haruhiko Tokuda7Osamu Kozawa8Department of Pharmacology, Gifu University Graduate School of Medicine, Gifu 501-1194, JapanDepartment of Pharmacology, Gifu University Graduate School of Medicine, Gifu 501-1194, JapanDepartment of Pharmacology, Gifu University Graduate School of Medicine, Gifu 501-1194, JapanDepartment of Pharmacology, Gifu University Graduate School of Medicine, Gifu 501-1194, JapanDepartment of Pharmacology, Gifu University Graduate School of Medicine, Gifu 501-1194, JapanDepartment of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, JapanDepartment of Orthopedic Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, JapanDepartment of Pharmacology, Gifu University Graduate School of Medicine, Gifu 501-1194, JapanDepartment of Pharmacology, Gifu University Graduate School of Medicine, Gifu 501-1194, JapanWe previously showed that the mitogen-activated protein (MAP) kinase superfamily, p44/p42 MAP kinase, p38 MAP kinase, and stress-activated protein kinase (SAPK)/c-Jun N-terminal (JNK), positively plays a part in the platelet-derived growth factor-BB- (PDGF-BB-) stimulated synthesis of interleukin-6 (IL-6), a potent bone resorptive agent, in osteoblast-like MC3T3-E1 cells while Akt and p70 S6 kinase negatively regulates the synthesis. In the present study, we investigated whether (-)-epigallocatechin gallate (EGCG), one of the major green tea flavonoids, affects the synthesis of IL-6 in these cells and the mechanism. EGCG significantly reduced the IL-6 synthesis and IL-6 mRNA expression stimulated by PDGF-BB, EGCG reduced the PDGF-BB-stimulated IL-6 synthesis also in primary-cultured osteoblasts. EGCG had no effect on the levels of osteocalcin and osteoprotegerin in MC3T3-E1 cells. The PDGF-BB-induced autophosphorylation of PDGF receptor β was not suppressed by EGCG. The PDGF-BB-induced phosphorylation of p44/p42 MAP kinase and p38 MAP kinase was not affected by EGCG. On the other hand, EGCG markedly suppressed the PDGF-BB-induced phosphorylation of SAPK/JNK. Finally, the PDGF-BB-induced phosphorylation of Akt and p70 S6 kinase was not affected by EGCG. These results strongly suggest that EGCG inhibits the PDGF-BB-stimulated synthesis of IL-6 via suppression of SAPK/JNK pathway in osteoblasts.http://dx.doi.org/10.1155/2008/291808 |
| spellingShingle | Shinji Takai Rie Matsushima-Nishiwaki Seiji Adachi Hideo Natsume Chiho Minamitani Jun Mizutani Takanobu Otsuka Haruhiko Tokuda Osamu Kozawa (-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK Mediators of Inflammation |
| title | (-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK |
| title_full | (-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK |
| title_fullStr | (-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK |
| title_full_unstemmed | (-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK |
| title_short | (-)-Epigallocatechin Gallate Reduces Platelet-Derived Growth Factor-BB-Stimulated Interleukin-6 Synthesis in Osteoblasts: Suppression of SAPK/JNK |
| title_sort | epigallocatechin gallate reduces platelet derived growth factor bb stimulated interleukin 6 synthesis in osteoblasts suppression of sapk jnk |
| url | http://dx.doi.org/10.1155/2008/291808 |
| work_keys_str_mv | AT shinjitakai epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk AT riematsushimanishiwaki epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk AT seijiadachi epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk AT hideonatsume epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk AT chihominamitani epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk AT junmizutani epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk AT takanobuotsuka epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk AT haruhikotokuda epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk AT osamukozawa epigallocatechingallatereducesplateletderivedgrowthfactorbbstimulatedinterleukin6synthesisinosteoblastssuppressionofsapkjnk |